Adsorption and Kinetics Studies of Cr (VI) by Graphene Oxide and Reduced Graphene Oxide-Zinc Oxide Nanocomposite.

In this work, graphene oxide (GO) and its reduced graphene oxide-zinc oxide nanocomposite (rGO-ZnO) was used for the removal of Cr (VI) from aqueous medium. By employing a variety of characterization techniques, morphological and structural properties of the adsorbents were determined. The adsorption study was done by varying concentration, temperature, pH, time, and amount of adsorbent. The results obtained confirmed that rGO-ZnO is a more economical and promising adsorbent for removing Cr (VI) as compared to GO. Kinetic study was also performed, which suggested that sorption of Cr (VI) follows the pseudo-first-order model. For equilibrium study, non-linear Langmuir was found a better fitted model than its linearized form. The maximum adsorption capacity calculated for GO and rGO-ZnO nanocomposite were 19.49 mg/g and 25.45 mg/g, respectively. Endothermic and spontaneous nature of adsorption was detected with positive values of ΔS (change in entropy), which reflects the structural changes happening at the liquid/solid interface.

Metal Based Bioactive Nitrogen and Oxygen Donor Mono and Bis Schiff Bases: Design, Synthesis, Spectral Characterization, Computational Analysis and Antibacterial Screening.

The scientific interest in developing the advanced metal based compounds to inhibit and control bacterial infections is continuously rising. Keeping in view their pharmacological significance, two new bioactive symmetrical phenylenediamine mono- and bis-Schiff bases, 2-{[(4-aminophenyl)imino]methyl}-6-methoxyphenol (L1) and 2,2'-{benzene-1,2-diylbis[nitrilomethylylidene]}bis(6-methoxyphenol) (L2) have been synthesized and characterized by using physical techniques, spectral methods, elemental and DFT based computational analysis with B3LYP/6-311++G(d, p) basis set. Furthermore, the synthesized ligands were complexed with VO, Mn, Co, Ni, Cu and Zn ions in ratio [M:L,1:2 and 1:1], respectively. All the complexes exhibited significant antibacterial action against all tested bacterial strains. But overall, the zinc complexes possessed higher antibacterial activity. These results concluded that metal complexes might be promising induction in the upcoming time for medical purposes.

Study of electric conduction mechanisms in bismuth silicate nanofibers.

This work represents the nature of conduction mechanism in bismuth silicate (BiSiO) nanofibers as a function of temperature and frequency. Scanning electron micrographs and X-rays diffraction patterns exhibited the formation of cubic phases of Bi4(SiO4)3 and Bi12SiO20 nanofibers respectively with an average diameter of ~200 nm. Temperature dependent (300 K-400 K) electrical characterization of fibers was carried out in frequency range of ~20 Hz-2 MHz. The complex impedance analysis showed contribution from bulk and intergranular parts of nanofibers in conduction. Moreover, analysis of the Cole-Cole plot confirmed the space charge dependent behavior of BiSiO nanofibers. Two types of relaxation phenomena were observed through Modulus analysis. In ac conductivity curve, step like feature of plateau and dispersive regions were described by Maxwell-Wagner effect while the dc part obeyed the Arrhenius law. However, frequency dependent ac conductivity revealed the presence of conduction mechanism in diverse regions that was ascribed to large polaron tunneling model. Detailed analysis of complex Impedance and ac conductivity measurement showed negative temperature coefficient of resistance for the BiSiO nanofibers. Current-voltage (IV) characteristics represented ohmic conduction; followed by space charge limited current conduction at intermediate voltages. Results from both ac and dc measurements were in good agreement with each other.

Structure-property correlations, defect driven magnetism and anomalous temperature dependence of magnetic coercivity in PbTi1-xFexO3 (0 ≤x≤ 0.5) systems.

The search for new multiferroic materials is on the rise due to their potential applications in an advanced generation of highly efficient multifunctional devices. Here we report a series of PbTi1-xFexO3 (0 ≤x≤ 0.5) samples prepared by a solid-state reaction method. Structural analysis suggests that doping of Fe introduces oxygen vacancies along the c-axis (aliovalent substitution; Fe3+→ Ti4+), local distortions and microstrains in the PbTiO3 lattice which triggered the partial structural transformation from tetragonal to cubic. This has been confirmed using structural analysis tools such as X-ray diffraction, Fourier Transform Infrared Spectroscopy, Raman spectroscopy, and Mössbauer spectroscopy. The presence of oxygen vacancies was further confirmed by refining the site occupancies through Rietveld refinement. Mössbauer measurements confirmed that Fe ions exist in the 3+ state and change in coordination of some Fe3+ ions from octahedral to tetrahedral points towards the oxygen deficiency in the system. Raman studies confirm the presence of all ordinary and quasi phonon modes in Fe doped PbTiO3 samples. The overlapping and weakening of modes are related to the structural changes/transformation. The modes' shifting to lower wavenumbers is ascribed to the increase in the average atomic mass at Ti-sites. The induced ferromagnetism in the system increases with an increase in the Fe content and can be explained on the basis of the F-center exchange mechanism. Moreover, we found an anomalous temperature-dependent trend in the magnetic coercivity (decrease in coercivity as the temperature is decreased) which can be explained in terms of a low-temperature decrease in an effective magnetic anisotropy when the effects of magneto-electric coupling are included. The existence of well-developed ferroelectric and ferromagnetic hysteresis loops confirmed the multiferroic nature of the system. The increase in the value of the dielectric constant at 1 MHz with an increase in the Fe content is attributed to the increase in resistivity of the system due to the formation of immobile defect dipole complexes.

Salem VAMC-U.S. Army Fort Bragg Warrior Transition Clinic telepsychiatry collaboration: 12-month operation clinical perspective.

OBJECTIVE: To describe the clinical experience in the first Veterans Affairs (VA)-U.S. Army Warrior Transition Clinic (WTC) telepsychiatry operation (September 2008-August 2009). MATERIALS: Joint VA and U.S. Army records. METHODS: Analysis of intake, follow-up, and last visit records. RESULTS: One hundred twenty active-duty U.S. Army soldiers were seen (394 clinic visits). Ninety-eight soldiers had one or more combat tours, principally in Iraq and Afghanistan. Posttraumatic stress disorder was diagnosed in 50.0% of the cases by the WTC telepsychiatrists. The majority of the soldiers had medical comorbidities, especially chronic pain (75.0%), in addition to mental health problems. Several of the soldiers were recovering from trauma (20.8%) and/or surgery (23.3%), 11.7% exhibited traumatic brain injuries, and 17.5% had headaches. Disrupted relationships (74.2%) were notable for non-family members, especially military cohorts such as other persons in the same WTC squad or platoon. CONCLUSION: The observations in this report come from a cross-section of soldiers who were triaged to meet WTC admission criteria. As this is the prototype VA-U.S. Army telepsychiatry collaboration, there are no comparative data at this time. The nature of the medical and psychiatric problems treated in the military WTC represents an index of the more severe combat trauma treated on military bases from ongoing combat operations and may predict future VA-U.S. Army collaborative telepsychiatry clinic experiences.

A telepsychiatry transition clinic: the first 12 months experience.

To improve the management of soldiers with combat-related mental health problems, an interdisciplinary telepsychiatry service was established between a clinic at the Fort Bragg army base and the Veterans Affairs (VA) Medical Center in Salem. In the first 12 months of operation, 120 soldiers (105 males) were seen in a total of 394 telepsychiatry sessions. The time spent on telepsychiatry by the six VA psychiatrists increased from 13 hours in the first month to 41 hours in the twelfth month. The number of telepsychiatry sessions increased from nine in the first month to 56 in the twelfth month. The mean global assessment of function score (GAF) in the soldiers increased significantly (P < 0.001) from 58.0 at intake to 62.3 at the last visit. Soldiers received VA telepsychiatry on average 22 days after the initial consultation with a primary care provider, a reduction of at least eight days compared to the previous delay. The majority of soldiers (89%) who were treated by VA psychiatrists enrolled in the VA within about six months of discharge. Similar VA-US Military collaborations may prove beneficial for other military bases that have returning combat soldiers.

Ruptured intracranial dermoid cyst presenting with neuropsychiatric symptoms: a case report.

Psychiatric symptoms associated with frontal lobe unruptured or ruptured intracranial dermoid cysts are rarely described in the medical literature. The case of a 58-year-old man with a chronic history of anxiety, major depression, and obsessive compulsive disorder who presented with new onset auditory and visual phenomena is described. This case illustrates the need to include an underlying brain tumor in the differential diagnosis when encountering new onset auditory and visual phenomena in patients with chronic mood and/or anxiety disorders.